There's really no way to answer that question; whether caching is beneficial is highly dependent on the details of the application. I always encourage users to load test and benchmark; try different combinations to see what works best. You say "it's inadmissible for me to have clear cache so often, as the entities after are loaded directly from dbs and traffic is incredible, server is very unstable then" so it sounds like you need a solution that avoids invalidating the cache. So is there anything you can do about the fact that "ejb3 queries in cases the entities are not cached are slowing down the operations, especially the load"? Are you annotating properties that don't have to be loaded with @java.persistence.Basic(fetch=LAZY)? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206139#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...